When choosing one of several options, we first estimate the subjective value of each option, then compare them, and finally choose the better one based on the comparison results.So far, it has been shown that the orbitofrontal cortex plays an important role in estimating value, but it was unclear where in the brain the estimated value was compared.

　In order to hypothesize that the comparison of values ​​may also be carried by the orbitofrontal cortex, and to test this, the research group conducted a reward value-based action selection task on red-tailed monkeys closely related to humans. We conducted an experiment to record the activity of nerve cells in the orbitofrontal cortex during task performance.As a result, the activity of neurons in the orbitofrontal cortex correlates with the difference in subjective value of the presented options, i.e., it is possible that neurons in the orbitofrontal cortex are making value comparisons. Was suggested.

　Subsequently, when the activity of the orbitofrontal cortex was pharmacologically inactivated, it was irrational to choose the one with the lower value, especially when the value of the option was close and it was difficult to choose which one to choose. It was confirmed that the frequency of selection was significantly increased.From this, it became clear at the nerve cell level that the orbitofrontal cortex is responsible for the value comparison of "which option is more valuable".

　Elucidation of the information processing process of selective behavior in the brain is expected to contribute significantly to the treatment of behavioral decision disorders due to brain region damage.In the future, the challenge is to clarify how the signals processed in the orbitofrontal cortex become the final choice and are output as actual actions.

Paper information:[Communications Biology] Neurons in the monkey orbitofrontal cortex mediate reward value computation and decision-making